Re: Out of free buffers... HELP!

Ok, can someone explain to me why this first query might run faster than the
second?

select src,dst,count(dst) from data;

select src,dst,count(*) from data;

I've always used the second form.  If the first is faster, I need to know.

Thanx,
Mike Diehl,
Network Monitoring Tool Devl.
Sandia National Laboratories.
(505) 284-3137
jdiehl@sandia.gov

> -----Original Message-----
> From: Haller Christoph [mailto:ch@rodos.fzk.de]
> Sent: September 18, 2001 7:18 AM
> To: jdiehl@sandia.gov
> Cc: pgsql-sql@postgresql.org
> Subject: Re: [SQL] Out of free buffers... HELP!
> 
> 
> As long as there are no nulls allowed in column 'dst' the 
> select src,dst,count(dst) from ... 
> should retrieve the same result. 
> Try it. It should run faster anyway. 
> Maybe there are other ways to word your query, but without 
> more knowledge about your table structure and intentions 
> I can't tell you what. 
> Alternatively, you may want to report your error to the 
> [HACKERS] mailing list - there you might even find more
> detailed support. 
> Regards, Christoph 
> > 
> > Hi all.
> > 
> > I sent this once before, but didn't see it appear on the 
> list...  So here we
> > go again...
> > 
> > I have a large query that I'm trying to run, but it never 
> finishes.  I
> > get an error message and it quits.
> > 
> > I'm doing:
> > 
> > psql ids -c 'select src,dst,count(*) from brick* where src_port=135
> > group by src,dst' > /tmp/135.dat
> > 
> > and I get:
> > 
> > ERROR:  out of free buffers: time to abort !
> > 
> > Any ideas on how to get this query to run?
> > 
> > Thanx,
> > Mike Diehl.
> > 
> > 
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